1. Field of the Invention
The present invention generally relates to storing and retrieving copy-protected data on a disc drive.
2. Background of the Related Art
With the advent of the recording and playing of digital data, the need to store copy-protected data on disc drives becomes increasingly a necessity. Digital data is rapidly becoming the standard format by which industries, such as the entertainment industry, record and play multimedia. Paid for programming available to the public such as movies, sound tracks, music recordings, and the like, are increasing in demand. With digital recording, the public has more options than ever to listen to and/or record digital audio and video with unparalleled recording and playback quality.
One exemplary storage system being used more frequently to store digital multi-media is a computer controlled disc-based storage drive, e.g., a disc drive. Disc drives are capable of storing large amounts of digital data in a relatively small area. Disc drives store information on one or more recording media. The recording media conventionally take the form of a circular storage disc, e.g., media, having a plurality of recording tracks. Conventional disc drives include a plurality of the storage discs, vertically aligned, and each with at least one magnetic head for reading or writing information to the media. Typically, the magnetic head is attached to a positioner arm assembly that uses servomotors, such as stepper motors, to align the magnetic head above the disc. The location of the magnetic head is typically determined by a disc controller that is given the position of a data area on the disc to read or write data. The precise location of the head is typically accomplished by incorporating a closed-loop electro-mechanical servo system with a dedicated servo region, or regions, used to provide relatively continuous feedback to the system to maintain accurate positioning of the data heads.
Unfortunately, due to the high quality of the data and the fact that the data stored on digital storage systems, such as disc drives, is often unprotected and easily copied, the copying and selling of unauthorized copies of digitally recorded material is on the rise. Consider the case where a paid for program such as an audio file is downloaded via a network of computers such as the Internet, to a disc drive for play by a client who has paid for the file. Often, the file may be copied to another storage media or to another disc drive for use by another user unless copy protection is used. This often referred to as xe2x80x9cpiratingxe2x80x9d a copy of the file. Additionally, the file may be repackaged and sold by others for profit without permission, often called xe2x80x9csoftware piracyxe2x80x9d. In addition, the files may be shared by other users by playing from the owner""s computer allowing the end user the benefit of the file without purchasing the file from the owner.
Conventional digital copy-protection schemes involve techniques such as registration, encryption, digital watermarking, 5C content, and the like. For example, software copy protection schemes often involve the use of copy-protection techniques that require issuing registration numbers with each package. When you install the software, you must enter the registration number. This technique does not prevent all unauthorized copying, but it limits it. In addition, users may not be able to obtain updates to a software product unless they own the original diskettes and documentation. Unfortunately, the user may forget, or may have difficulty in registering the software and may become frustrated if the software stops working and/or working properly.
For conventional multimedia, data stored on optical surfaces such as found on a digital versatile disc (DVD) is often copy protected. For example, the digital-video format includes a content scrambling system (CSS) to prevent users from copying discs. The DVD system may also use key based techniques such as the SC technique that has software keys that expire after use. Unfortunately, this means that today""s DVD players may not be able to play DVD-video discs without a software and/or hardware upgrade to decode the encrypted and/or keyed data even though the use may be authorized.
Another issue with conventional copy protection is that of making backups of the data. For example, a user may have a computer that they need to backup the data, conventional encryption techniques often require that a hardware and/or specific software key(s) be used before the data can be successfully copied. Unfortunately, the user may not have the correct hardware or software key to allow the transfer of the data and may become frustrated.
Furthermore, most conventional copy protection techniques such as CSS are defeated over time causing the digital-video and software industry to constantly upgrade the hardware, and/or software techniques to combat the unauthorized copying. The constant upgrading and development of protection techniques that are eventually exposed and defeated causes an increase in the cost of the product as well as possible incompatibility issues with existing systems.
Thus, what is needed is a method that allows the recording and playing of copy protected material to the user without the ability to copy the data or use the data in an unauthorized manner without affecting the compatibility of the storage device to operate with non-copy protected data.
The present invention generally provides a method and apparatus for storing and retrieving copy protected data within storage devices such as a disc drive. One aspect of the present invention provides a method for writing on a disc drive data to be copy protected, the steps include providing data to be copy protected, copying a first data table to a second data table writing the data to be copy protected to a least one data sector within at least a first data wedge and modifying, within the first data list, the status of at least one servo wedges adjacent and corresponding to the data wedge, as defective.
Another aspect of the invention provides a method for reading copy protected data from a disc drive, the steps include determining if a request to read copy protected data has been issued, and if the request to read copy protected data has not been issued then reading at least one first servo status from a first data table wherein the first servo status indicates the a servo wedge as defective, but, if the request to read copy protected data has been issued then reading a second servo status from a second data list which indicates the servo wedge as valid and reading the data from the corresponding data wedge.
One aspect of the present invention provides a disc drive system comprising a signal-bearing media means for storing data, a code memory means coupled to a read/write controller means for controlling the reading and writing of data to the signal-bearing media, a means for reading and writing the data to the signal-bearing media and a processor means coupled to the code memory and the read/write controller. The processor includes a program which, when executed on the processor for a write sequence, is configured to perform the steps of copying a first data table to a second data table, writing data to be copy protected to at least one data wedge of the signal-bearing media, and modifying, within the first data table, the status of at least one servo wedge corresponding to the data wedge, as defective. When the program is executed on the processor for a read sequence, is configured to perform the steps of determining if a request to read copy protected data has been issued, if the request to read copy protected data has not been issued then reading at least one first servo wedge status from the first data table wherein the servo status indicates the location of the data as defective, but, if the request to read copy protected data has been issued then reading a second servo wedge status data from the second data table wherein the servo status indicates the location of the data as valid and reading the data.